Most of the glass sheets for vehicles and buildings are manufactured by a float process, and the glass sheets are called soda-lime-silica glasses due to their basic components. For a window opening for a vehicle and a building, from the viewpoint of the energy saving, an infrared absorbent glass is required. For improving the infrared absorption capacity of the soda-lime-silica glass, an absorption by ferrous oxide (FeO) is utilized.
In addition to the absorption of infrared radiation, the window glass is required to absorb ultraviolet radiation, while required to have a high transmittance of visible light. In particular, with respect to the window glass for a vehicle such as a passenger car, a visible light transmittance to be achieved, which depends on its specific location, is regulated by law in order to ensure visibility. Although the visible light transmittance to be achieved differs country by country, the typical standard is 70% or more.
An infrared and ultraviolet absorbent soda-lime-silica green glass containing about 0.51 to 0.96% by weight Fe2O3, about 0.15 to 0.33% by weight FeO and about 0.2 to 1.4% by weight CeO2 has been disclosed in JP-A-3-187946. This glass sheet has a visible light transmittance of 70% or more when it has a thickness of about 3 to 5 mm.
Infrared and ultraviolet absorbent soda-lime-silica green glasses have been disclosed also in JP-A-4-231347 and JP-A-6-166536.
On the other hand, a technique to absorb infrared radiation with functional fine particles dispersed in an interlayer film of a laminated glass without relying on glass components has been proposed. A laminated glass using an interlayer film in which ITO (conductive tin-containing indium oxide) ultra-fine particles having a particle size of 0.1 μm or less are dispersed has been disclosed in JP-A-8-259279. This laminated glass reduces scattering of visible light since the size of the ITO fine particles is small.